Modern medical science is constantly searching for new and more powerful agents to prevent, treat or retard bacterial and viral infections and cure the diseases they cause. Bacterial and viral infections of humans and domestic animals cost billions of dollars annually. Vast sums of money are spent each year by pharmaceutical companies to identify, characterize, and produce new antibiotics and antivirals to combat the emerging drug resistant strains which have become a serious problem. Reliable prophylactic treatments for disease prevention are also of major interest.
Specifically periodontal disease and dental caries are of major public health and economic interest worldwide. It is now widely recognized that both of these oral diseases are caused by bacteria which grow in masses on the teeth and in the gingival and subgingival areas. A commonly used descriptive term for these bacterial masses is “dental plaque”. In the case of periodontal disease, it has been reported that dental plaque bacteria, growing in the area where the teeth and gingival tissues meet, cause an inflammation of the gingiva called “gingivitis”. This is characterized by swollen, edematous gingiva (“gums”) which are reddened and bleed easily. If plaque removal is inadequate, gingivitis may progress to “periodontitis” or periodontal disease in some individuals. Periodontitis generally is characterized by a chronic inflammation of the tissues around the teeth, which leads to a resorption of supporting bone. Periodontal disease is the leading cause of tooth loss among adults.
Dental caries (cavities) are also caused by bacteria, with mutans Streptococcus being the principal etiologic agent. Dental caries is a prevalent and costly disease throughout the world. The latest report by NIH indicated that 49% of 12-year-old and 79% of 17-year-old children in the USA have dental caries. A very high percentage of the elderly also have tooth decay manifest as root caries.
Tooth decay is mainly caused by a group of cariogenic Gram-positive bacteria such as Streptococcus mutans. Given a suitable carbohydrate nutrient (simple dimer sugars like sucrose), these bacteria produce insoluble glucans and acids in dental plaque. The glucans produced by S. mutans are very sticky, enabling it to adhere to the tooth's surface while the acids attack the tooth's mineral structure causing demineralization that may lead to cavitation.
The prevention of dental plaque or the removal thereof has long been the focus of development, with the ultimate goal of inhibiting both caries and periodontal diseases. While the formation of dental plaque can be inhibited to a certain extent by brushing the teeth at frequent intervals, brushing alone is not sufficient to effectively prevent the formation of dental plaque or remove substantially all of the dental plaque that has formed on the teeth. Since brushing alone is often not sufficient to prevent dental caries or periodontal disease due to the nature of the pathogenic plaque bacteria, chemical methods using anti-bacterials such as chlorhexidine, benzalkonium chloride, and cetylpyridinium chloride have been proposed.
There is a need in the art to provide compositions and methods useful for treating or preventing microbial conditions, e.g., oral or mucosal surface microbial conditions.